There was a time when chimpanzees were thought to be simple beasts, nothing like us impressive, intelligent humans. But decades of studying our hairy relatives have revealed some incredibly human-like behaviours. Chimps use tools, solve puzzles and their social interactions can be so complex that one eminent researcher wrote a whole book about "chimpanzee politics". And now, new video footage confirms that chimps are also teachers.

Researchers from Washington University in St. Louis had set up remote cameras in the forests of Nouabalé-Ndoki National Park in the Republic of Congo to study the local chimp population. When the footage was examined, the scientists discovered that they had captured footage of mothers teaching their young to use tools – the first documented evidence of such behaviour. 

Chimps are famous for their tools-wielding skills. They use twigs to pull termites out of their mounds; they use rocks to crack tough nuts; they use chewed-up leaves to make sponges for collecting water; and there are even reports of chimps creating sharpened spears for hunting small animals. But just like in humans, this complex behaviour doesn't come automatically. Young chimps must be taught.

"We found that mother chimpanzees in the Goualougo Triangle teach by transferring termite-fishing probes to their offspring," says Stephanie Musgrave, the Washington University graduate student who led the study. "In this population, chimpanzees select specific herb species to make their fishing probes, and they produce probes that have a particular brush-tipped design. By sharing tools, mothers may teach their offspring the appropriate material and form for manufacturing fishing probes."

The videos show some remarkable behaviour. In some cases, young chimps can be seen begging and squeaking until mom hands over her termite-catcher and has to go find a new one for herself. At another point, a mom gives up her own skillfully crafted tool in exchange for a youngster's botched attempt (and then fixes up the shoddy probe for her own use!). One clever female chimp was observed bringing two tools to a termite mound, knowing that her youngster would be bothering her before long.  

Caption: This young chimp is having little success, so mom swaps her well-made tool for her child’s. Video courtesy of Goualougo Triangle Ape Project.

The footage is impressive – but what makes this teaching, rather than just sharing or stealing? One major factor is that this tool-transferring behaviour happens "in the presence of a learner". It's very rare for adult chimps to swap tools with each other, but these videos captured almost a hundred instances of moms passing on tools to their offspring, as well as one adorable case of a young-adult chimp handing a tool over to her baby sister. 

The other big criterion for teaching behaviour is that it's a give-and-take scenario. The young chimp learners had a much easier time termite-hunting after receiving tools from the adult, while moms had to give up their own feeding success for the sake of their little ones. But chimp intelligence is not to be underestimated – the videos also capture a couple of instances of mom splitting her own tool in half, saving herself the trouble of finding a new one.

Caption: In this video, mom splits her own tool down the middle so she and her child can collect termites together. Video courtesy of Goualougo Triangle Ape Project.

Crickette Sanz, associate professor of biological anthropology at Washington University, says the use of remote video cameras is a real game-changer for researchers who study chimps. "We have observed a generation of chimpanzee kids learn how to use these tool sets, without having to spend a decade habituating them to human presence or risk exposing them to anthropogenic disease."

Watching chimps using tools and teaching their offspring is really fascinating, but there is also a personal connection: in chimps, we can't help but see reflections of ourselves. "Studying how young chimpanzees learn the tool skills particular to their group helps us to understand the evolutionary origins of culture and technology, and to clarify how human cultural abilities are similar to or different from those of our closest living relatives," says Musgrave.

Top header image: Tim Callaghan, Flickr